From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 116489445 for ; Thu, 9 Mar 2023 11:13:13 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 5D51921E8A; Thu, 9 Mar 2023 11:13:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1678360391; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+3YUrWV7jfpXoA++JeKVk7hZ9f1CmC3d5xDMhvCnqQY=; b=vEtLBCb2yry/emu/jQIc82ZS1qlwzsWUD3kbJjRDcSQH1Plr6grvNfNZcmXccfFFnXIVOJ KXC3aZGxY+Q4fR2CySOSWAp5CLIId9rmeDxY7aMapaHDH2HsOYxzL7hfo+3kQUVZBHKdau tbbQR77ynnrN30wYRBqIe6kqhTK7okQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1678360391; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+3YUrWV7jfpXoA++JeKVk7hZ9f1CmC3d5xDMhvCnqQY=; b=uW6jZY4OeymUbTM2/kEI4rtBKz9eeX37/5LcvI4Yc+ms/o0L55GgSWDvQw5rEuIxSmmxfT kLvXbh1WeGCFo0Dg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 3E55F13A73; Thu, 9 Mar 2023 11:13:11 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id wFGoDke/CWRiRwAAMHmgww (envelope-from ); Thu, 09 Mar 2023 11:13:11 +0000 From: Vlastimil Babka To: Andrew Morton Cc: "Liam R. Howlett" , Matthew Wilcox , linux-mm@kvack.org, linux-kernel@vger.kernel.org, patches@lists.linux.dev, maple-tree@lists.infradead.org, Vlastimil Babka Subject: [PATCH 03/10] mm/mmap/vma_merge: use the proper vma pointers in cases 1 and 6 Date: Thu, 9 Mar 2023 12:12:51 +0100 Message-Id: <20230309111258.24079-4-vbabka@suse.cz> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230309111258.24079-1-vbabka@suse.cz> References: <20230309111258.24079-1-vbabka@suse.cz> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Case 1 is now shown in the comment as next vma being merged with prev, so use 'next' instead of 'mid'. In case 1 they both point to the same vma. As a consequence, in case 6, the dup_anon_vma() is now tried first on 'next' and then on 'mid', before it was the opposite order. This is not a functional change, as those two vma's cannnot have a different anon_vma, as that would have prevented the merging in the first place. Signed-off-by: Vlastimil Babka --- mm/mmap.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 1af4c9bc2c87..c33237b283c9 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -605,7 +605,7 @@ static inline void vma_complete(struct vma_prepare *vp, /* * In mprotect's case 6 (see comments on vma_merge), - * we must remove the one after next as well. + * we are removing both mid and next vmas */ if (vp->remove2) { vp->remove = vp->remove2; @@ -948,13 +948,14 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, /* Can we merge both the predecessor and the successor? */ if (merge_prev && merge_next && is_mergeable_anon_vma(prev->anon_vma, next->anon_vma, NULL)) { - remove = mid; /* case 1 */ + remove = next; /* case 1 */ vma_end = next->vm_end; - err = dup_anon_vma(prev, mid); + err = dup_anon_vma(prev, next); if (mid != next) { /* case 6 */ + remove = mid; remove2 = next; - if (!mid->anon_vma) - err = dup_anon_vma(prev, next); + if (!next->anon_vma) + err = dup_anon_vma(prev, mid); } } else if (merge_prev) { err = 0; /* case 2 */ -- 2.39.2